Safety door assembly for vehicle lift

ABSTRACT

An improved safety door unit for covering the open top of a lift floor box when the lift is elevated. The unit includes a pair of articulated door panels on each side of the lift shaft. A nonrotator carried by the lift for each pair of door panels, respectively, engages one door panel of the corresponding pair to raise it from a horizontal retracted position to a horizontal operative position, and the one panel has a projection for engaging and pivoting the other door panel about a horizontal hinge line from an inclined, retracted position to a horizontal, operative position of the one panel.

United States Patent Feudale [451 Nov. 27, 1973 SAFETY DOOR ASSEMBLY FOR VEHICLE LIFT [75 Inventor: Victor John Feudale, South San Francisco, Calif.

[73] Assignee: J.D. Cochin Manufacturing 1 Company, South San Francisco,

Calif.

[22] Filed: Apr. 28, 1972 21 Appl. No.: 248,688

[52] US. Cl. 187/8.62

[51] Int. Cl B66f 7/18 [58] Field of Search l87/8.61, 8.62, 62

[56] References Cited UNITED STATES PATENTS 3,608,675 9/1971 Sherry l87/8.62 2,655,224 10/1953 Hott l87/8.62

Primary Examiner-Edward A. Sroka Attorney-Stephen S. Townsend et al.

[57] ABSTRACT An improved safety door unit for covering the open 7 top of a lift floor box when the lift is elevated. The unit includes a pair of articulated door panels on each side of the lift shaft. A non-rotator carried by the lift for each pair of door panels, respectively, engages one door panel of the corresponding pair to raise it from a horizontal retracted position to a horizontal operative position, and the one panel has a projection for engaging and pivoting the other door panel about a horizontal hinge line from an inclined, retracted position to a horizontal, operative position of the one panel.

13 Claims, 4 Drawing Figures SAFETY DOOR ASSEMBLY FOR VEHICLE LIFT This invention relates to improvements in the covering of open top floor boxes for vehicle lifts and, more particularly, to an improved safety door assembly operated by the non-rotator of a vehicle lift.

Vehicle lifts are nor generally made so that they can be retracted in a floor box below a surface, so that a vehicle can readily move onto and off the lift merely by moving over the surface. The eliminates platforms and other structures for supporting lifts. v

The floor box of such a lift has an open top which is covered by safety panels when the lift is retracted into the box. When the lift is elevated, the open top of the box must also be covered to allow a workman to move about beneath the elevated lift without having to look down before taking the next step. While safety panels have been used in the past for covering such an open top of the floor box, such panels are complicated in constuction and generally do not safely support the weight of a workman or his tools while working on an elevated vehicles. Also, such panelsv have numerous moving parts which could become rusty due to a standing water in the bottom of the .floor box, thereby causing malfunctions of the panels and requiring frequent maintenance. Also, the open top of the floor box has not been completely closed by conventional safety panels because projections remain which could cause the workman to trip when he moves around while looking upwardly.

The present invention is directed to improvements in lift floor boxes by providing an improved safety door assembly for the open top of a lift floor box to cover the same when the lift thereof is elevated. The door assembly comprises a pair of shiftably coupled door panels on each side of the lift, respectively, one panel being hinged to the floor box and the other panel being connected by a pivotal, elongated crank to the one panel. The actuator for moving each pair of door panels from retracted to operative positions includes a non-rotator ordinarily provided for the lift and operable to effect movement of the door panels as the lift approaches its fully elevated position.

When the lift is fully elevated, the door panels are completely horizontal and cover the open top of the floor box. Thus, no obstructions project upwardly from the box which would otherwise cause a workman to be tripped while moving back and forth under the elevated lift. Moreover, each pair of panels has support means which will safely and reliably support the workman and his hools.

The non-rotator for each pair of door panels has a rod provided with a shoulder for engaging a first of the door panels and elevating the same from a horizontal, retracted position to a horizontal, operative position flush with the open top of he box. This occurs at a specifrc time, such as when the lift is almost but not quite fully elevated. The first door panel has a lateral projection which engages the second door panel and causes the latter to move from an inclined, retracted position to a hoirzontal, operative position flush with the open top of the box. This occurs when the first door panel is being elevated by the shoulder of the non-rotator. The movements of the door panels are reversed as the nonrotator is lowered as the lift itself is lowered. the fact that the second panel is inclined when it is in its retracted position allows the invention to be used with lifts having yokes provided with inclined end legs.

The primary object of his invention is to provide an improved safety door assem bly for an open top lift floor box wherein the open top is completely covered by the assembly when the lift is elevated and has no upward projections, yet the assembly provides a safe and reliable support for a workman and his tools.

A further object of this invention is to provide an improved lift floor box having an improved safety door assembly comprised of relatively shiftable door panels operated by the non-rotator of the lift itself so that the door panels will be moved sequentially into operative positions flush with the open top of he box upon elevation of the lift so as to eliminate the various additional structures which have been required on conventional safety door mechanisms for actuating the same.

Other objects of this invention will become apparent as the following specification progresses, reference being had to the accompanying drawings for an illustration of the invention.

In the drawings:

FIG. 1 is a perspective view of a vehicle lift including a floor box provided with the safety door assembly of this invention;

FIG. 2 is an enlarged, fragmentary, cross-sectional view showing the positions of the door panels of the safety door assembly when the lift is elevated;

FIG. 3 is a perspective of the door panels looking from beneath; and

FIG. 4 is a view similar to FIG. 2 but showing the retracted positions of the lift and the door panels.

The vehicle lift assembly utilizing the present invention is broadly denoted by the numeral 10 and includes a cylindrical shaft 12 having a yoke 14 mounted on the upper end thereof. Yoke M has a mounting beam 16 which extends in opposite directions from the upper end of shaft 12. A pair of inclined legs 18 are secured to the outer ends of beam 16 and end pads 20 are secured to the upper ends of respective legs 18. Vehicle support arms 22 are pivotally mounted on respective pads 20 so as to underlie and engage a vehicle frame to raise the same when shaft 12 is elevated out of a cylindrical housing 24 buried in the ground.

Housing 24, as shown in FKGS. 2 and 4, has its upper end near the bottom 26 of an elongated lift floor box 28 having a rectangular open top 29. For purposes of illustration, box 28 is formed of concrete but it can be of other materials as well. All of the foregoing components of vehicle lift assembly 10 are conventional in construction.

The purpose of lift floor box 28 is to allow yoke 14 to be retracted below ground level as shown in FIG. 4 so that arms 22 will be on the supporting surface which is substantially flush with the plane of the open top 29. Thus, a vehicle can be driven over the surface and into a position above the lift. By manipulating arms 22, they can be made to underlie portions of the vehicle frame and to engage and lift the same as shaft 12 is elevated.

Generally a vehicle lift of this type has a non-rotator which prevents rotation of the lift as it is raised and lowered. Lift 10 has a pair of non-rotators 30 and 32, each non-rotator being of substantially the same construction and including an outer tube 34 and an inner rod 36 movable up and down within the tube 34. The upper end of tube 34 terminates near bottom 26 of box 28 as shown in H68. 2 and 4. Rod 36 has an upper, cylindrical segment 38 and a lower, cylindrical segment 40 whose diameter is greater than that of segment 38 to present an annular shoulder 42 (FIG. 4) between the ends of the rod and near its lower end.

A safety door assembly 44 is provided for each nonrotator respectively, for covering a respective portion of open top 29. Each safety door assembly includes a first door panel 46 hingedly mounted at one end margin to the upper margin of the adjacent end wall 54 of box 28, and a second door panel 48 shiftably coupled with a corresponding first door panel 46 and disposed between the latter and shaft 12. Door panels 46 and 48 are generally of a structurally rigid material, such as sheet steel or the like, to support the weight of a workman and certain tools when the door panels cover top 29 of box 28 as shown in FIG. 1. This will allow the workman to move safely beneath a vehicle on lift 10.

Each door panel 46 is generally square or rectangular and has a pair of spaced hinges 50 secured to an angle member 52 imbedded in the adjacent end wall 54 of box 28. Thus door panel 46 can pivot about a generally horizontal axis which is located to permit door panel 46 to pivot from its retracted, inclined position (FIG. 4) to its operative, horizontal position (FIG. 2) in the plane of open top 29. Each door panel 46 has a pair of sleeves 56 near the opposite end margin 58 thereof and adjacent to and substantially parallel with corresponding side margins of the panel.

Each door panel 48 has a first end margin provided with an arcuate edge 60 which is adapted to surround the adjacent side portion of shaft 12 as shown in FIG. 3. Otherwise, panel 48 is substantially rectangular.

The opposite end margin 64 of panel 48 is provided with a pair of spaced, aligned sleeves 62 which are parallel to margin 64 and pivotally receive first segments 66 of respective L-shaped guide rods 68 whose second segments 70 are shiftably received within respective sleeves 56 of the adjacent door panel 46 as shown in FIGS. 2, 3 and 4.

Each door panel 48 has a hole 72 aligned with rod 36 and of a size permitting upper segment 48 to move therethrough. An annular flange 74 is rigidly secured to the lower surface of each door panel 48 in surrounding relationship to hole 72. Flange 74 is adapted to be engaged by shoulder 42 as rod 36 is elevated so that shoulder 42 will cause elevation of door panel 48 at a specific time during the upward movement of rod 36, such as when yoke 14 approaches the upper end of its path of travel. This will cause door panel 48 to be moved from its retracted, horizontal position shown in FIG. 4 to its operative, horizontal position shown in FIGS. 1-3. In the latter position, door panel 48 will be in the plane of open top 29 in end-to-end relationship with the adjacent door panel 46. Also, the shapes of each pair of door panels 46 and 48 are such that they close substantially the entire open portion of open top 29 on the corresponding side of shaft 12.

A pair of parallel rigid bars 76 are secured to the underside of door panel 48 and have respective extensions 77 extending beyond end margin 64 so that extensions 77 underlie the adjacent door panel 46. Thus, extensions 77 can engage door panel 46 and move it from its retracted, inclined position of FIG. 4 to its operative, horizontal position of FIGS. 1-3 in response to the upward movement of the corresponding door panel 48.

In operation, and with the various parts assembled as shown in the drawings, shaft 12 will initially be in its retracted or lowered position (FIG. 4). When vehicle lift is in this condition, cover plates 78 and 80 will cover open top 29. These cover plates are conventional and form no part of this invention.

When it is desired to elevate arms 22, fluid pressure is exerted on the lower end of shaft 12 causing it to raise out of housing 24 relative to lift box 28. As shaft 12 is raised, yoke 14 carries cover plates 78 and upwardly and open top 29 becomes exposed. During the initial phase, door panels 46 and 48 on each side of shaft 12 remain in their retracted positions (FIG. 4). During the elevation of shaft 12, the non-rotator rods 36 will also be raised because the upper end of each rod 36 is connected to yoke 14. Eventually, shoulder 42 of each rod 36 will engage the corresponding annular flange 74 on the 10 corresponding door panel 48. This will cause the door panel 48 to be raised while it remains generally horizintal. As each door panel 48 is raised, the ocrresponding guide rods 68 slide through sleeves 56 on the adjacent doorpanel 46. Also, each pair of extensions 77 eventually engage and raise the corresponding door panel 46 causing it to pivot upwardly, Cranks 68 continue to slide in sleeves 56 during this time. When door panels 46 and 48 reach their horizontal, operative positions in the plane of open top 29, lift 10 will be in its elevated, operative position.

When the door panels are in their operative positions, they are sufficiently supported from beneath to permit a workman to move safely around the underside of the vehicle without being concerned about collapse of the door panels. The reason for this is that door panels 48 are supported adequately on shoulders 42 and door panels 46 are supported on extensions 77. Also, there are no projections extending upwardly from the plane of open top 29 when the door panels close the same since the door panels are all horizontally disposed. Moreover, the workman can safely roll carts containing tools onto and off the door panels as he stands thereon.

When it is desired to lower the lift, the door panels commence to move downwardly immediately toward their retracted positions as rods 36 are lowered. During this time, door panels 48 remain horizontal and panels 46 move toward and into their inclined positions (FIG. 4). Eventually, flanges 74 will engage the upper ends of respective tubes 34 thereby preventing downward movement of panels 48. In this case, door panels 46 will be at an angle sufficient to accommodate the presence of inclined legs 18 of yoke 14.

I claim:

1. In a vehicle lift assembly: a lift floor box having an open top and adapted to receive a vehicle lift when the latter is in a retracted position; a pair of safety door panels for each side of the lift respectively, one of the door panels being hingedly mounted on said box near said open top and shiftably connected to the other dor panel; a non-rotator adapted to be secured to said lift for up and down movement therewith and having means for raising the other door panel from a retracted position in the box below said open top to an operative position substantially flush with said open top as the non-rotator is moved upwardly by said lift, said other door having means for pivoting said one door panel from a retracted location extending into the box to an operative location substantially flush with said open top as the other door panel is raised.

2. In a vehicle lift assembly: a lift floor box having an open top and adapted to extend into a supporting surface with the open top substantially flush with said surface; a vehicle lift including a vertically reciprocal lift shaft extending through the bottom of the box; a pair of vertically reciprocal non-rotators coupled with 'the lift for preventing rotation thereof as the lift is raised and lowered; and a safety door assembly for each side of the shaft, respectively, each assembly being coupled with a respective non-rotator and movable from a retracted position within the box below said open top to an operative position substantially flush with a corresponding portion of said open top of the box in re sponse to the upward movement of the non-rotator.

3. In a vehicle lift as set forth in claim 2, wherein each non-rotator includes a rod having a shoulder for engaging the corresponding door assembly as the lift approaches the upper end of its path of travel.

4. In a vehicle assembly: an elongated lift floor box having an open top and adapted to receive a vehicle lift when the latter is in a retracted position; a pair of safety door panels for each side of the lift, respectively, a first of the door panels of each pair having a pair of opposed end margins; means hingedly mounting one of the end margins of each first panel of said box at a corresponding end thereof for pivotal movement from an inclined, retracted position within the box to a horizontal, operative position in the plane of said open top; a non-rotator for each pair of door panels, respectively, each nonrotator adapted to be secured to said lift for up and down movement therewith and having means for raising the second door panel of a corresponding pair from a substantially horizontal, retracted position within the box to a horizontal, operative position in the plane of said open top as the non-rotator is moved upwardly by the lift; and means on each second door panel for moving the corresponding first door panel into its operative position as the second door panel is raised by the corresponding non-rotator.

5. In a vehicle lift assembly as set forth in claim 4, wherein is provided guide means shiftably interconnecting the first and second door panels of each pair.

6. In a vehicle lift assembly as set forth in claim 5, wherein said guide means includes a pair of L-shaped guide rods, each guide rod having one segment pivotally coupled to the corresponding second door panel and another segment extending toward the corresponding first door panel, the latter having a sleeve aligned with and shiftably receiving the second segment of the corresponding guide rod.

7. In a vehicle lift assembly as set forth in claim 4, wherein the combined areas of the door panels of each pair are substantially equal to the area of said open top on one side of the vehicle lift so that each pair of door panels substantially covers the corresponding portion of said open top when the door panels are in their operative positions.

8. In a vehicle lift assembly as set forth in claim 4, wherein each non-rotator includes a vertically reciprocal rod having a shoulder intermediate its ends for engaging the corresponding second door panel.

9. In a vehicle lift assembly as set forth in claim 8, wherein each second door panel has a hole aligned with the rod of the corresponding non-rotator, one portion of the rod having a diameter less than that of the hole so that said one portion can move therethrough, the rod having a second portion provided with a diameter greater than the hole, the upper end of the second portion defining said shoulder.

10. In a vehicle lift assembly: a lift floor box having an open top and adapted to extend into a supporting surface with the open top substantially flush with said surface; a vehicle lift including a vertically reciprocal lift shaft extending through the bottom of the box; a pair of vertically reciprocal non-rotators coupled with the lift for preventing rotation thereof as the lift is raised and lowered; and a safety door assembly for each side of the shaft, respectively, each assembly being coupled with a respective non-rotator and movably from a retracted position within the box to an operative position substantially flush with a corresponding portion of said open top of the box in response to the upward movement of the non-rotator, each assembly including a first door panel hinged to the box at one end thereof and a second door panel shiftably coupled to the first door panel, said door panels being substantially sideby-side and coplanar with each other when the corresponding assembly is in operative position, said first door being inclined and the second door being generally horizontally disposed when the corresponding assembly is in its retracted position.

11. In a vehicle lift assembly: a lift floor box having an open top and adapted to extend into a supporting surface with the open top substantially flush with said surface; a vehicle lift including a vertically reciprocal lift shaft extending through the bottom of the box; a pair of vertically reciprocal non-rotators coupled with the lift for preventing rotating thereof as the lift is raised and lowered; and a safety door assembly for each side of the shaft, respectively, each assembly being coupled with a respective non-rotator and including a pair of relatively shiftable door panels, one of the door panels being inclined and the other door panel being generally horizontally disposed when the corresponding assembly is in a retracted position, the other door panel being moveable upwardly by the corresponding nonrotator and having a lateral projection for engaging and elevating said one door panel, whereby the door panels move into respective operative positions substantially flush with a corresponding portion of the open top of the box as a function of the upward movement of the non-rotator.

12. In a vehicle lift as set forth in claim 11, wherein said one door panel of each mechanism is hinged to said floor box near one end thereof, said one door panel having a sleeve at its innermost extremity, the other door panel having a rod pivotally mounted thereon and shiftably extending through said sleeve.

113. A vehicle lift assembly comprising: a lift floor box having an open top; a vehicle lift having means for raising and lowering the same relative to said floor box, said lift being at least partially receivable with the floor box when the lift is in, a retracted position; a pair of safety door panels for each side of the lift respectively, one of the door panels being hingedly mounted on said box and shiftably connected to the other door panel; a non-rotator for each pair of door panels respectively, said non-rotator being secured to said lift for up and down movement therewith and having means for raising the other door from retracted position in the box to an operative position substantially flush with said open top as the non-rotator is moved upwardly by said lift, said other door having means for pivoting said one door from a retracted location to an operative location substantially flush with said open top as the other door is raised. 

1. In a vehicle lift assembly: a lift floor box having an open top and adapted to receive a vehicle lift when the latter is in a retracted position; a pair of safety door panels for each side of the lift respectively, one of the door panels being hingedly mounted on said box near said open top and shiftably connected to the other do r panel; a non-rotator adapted to be secured to said lift for up and down movement therewith and having means for raising the other door panel from a retracted position in the box below said open top to an operative position substantially flush with said open top as the non-rotator is moved upwardly by said lift, said other door having means for pivoting said one door panel from a retracted location extending into the box to an operative location substantially flush with said open top as the other door panel is raised.
 2. In a vehicle lift assembly: a lift floor box having an open top and adapted to extend into a supporting surface with the open top substantially flush with said surface; a vehicle lift including a vertically reciprocal lift shaft extending through the bottom of the box; a pair of vertically reciprocal non-rotators coupled with the lift for preventing rotation thereof as the lift is raised and lowered; and a safety door assembly for each side of the shaft, respectively, each assembly being coupled with a respective non-rotator and movable from a retracted position within the box below said open top to an operative position substantially flush with a corresponding portion of said open top of the box in response to the upward movement of the non-rotator.
 3. In a vehicle lift as set forth in claim 2, wherein each non-rotator includes a rod having a shoulder for engaging the corresponding door assembly as the lift approaches the upper end of its path of travel.
 4. In a vehicle assembly: an elongated lift floor box having an open top and adapted to receive a vehicle lift when the latter is iN a retracted position; a pair of safety door panels for each side of the lift, respectively, a first of the door panels of each pair having a pair of opposed end margins; means hingedly mounting one of the end margins of each first panel of said box at a corresponding end thereof for pivotal movement from an inclined, retracted position within the box to a horizontal, operative position in the plane of said open top; a non-rotator for each pair of door panels, respectively, each non-rotator adapted to be secured to said lift for up and down movement therewith and having means for raising the second door panel of a corresponding pair from a substantially horizontal, retracted position within the box to a horizontal, operative position in the plane of said open top as the non-rotator is moved upwardly by the lift; and means on each second door panel for moving the corresponding first door panel into its operative position as the second door panel is raised by the corresponding non-rotator.
 5. In a vehicle lift assembly as set forth in claim 4, wherein is provided guide means shiftably interconnecting the first and second door panels of each pair.
 6. In a vehicle lift assembly as set forth in claim 5, wherein said guide means includes a pair of L-shaped guide rods, each guide rod having one segment pivotally coupled to the corresponding second door panel and another segment extending toward the corresponding first door panel, the latter having a sleeve aligned with and shiftably receiving the second segment of the corresponding guide rod.
 7. In a vehicle lift assembly as set forth in claim 4, wherein the combined areas of the door panels of each pair are substantially equal to the area of said open top on one side of the vehicle lift so that each pair of door panels substantially covers the corresponding portion of said open top when the door panels are in their operative positions.
 8. In a vehicle lift assembly as set forth in claim 4, wherein each non-rotator includes a vertically reciprocal rod having a shoulder intermediate its ends for engaging the corresponding second door panel.
 9. In a vehicle lift assembly as set forth in claim 8, wherein each second door panel has a hole aligned with the rod of the corresponding non-rotator, one portion of the rod having a diameter less than that of the hole so that said one portion can move therethrough, the rod having a second portion provided with a diameter greater than the hole, the upper end of the second portion defining said shoulder.
 10. In a vehicle lift assembly: a lift floor box having an open top and adapted to extend into a supporting surface with the open top substantially flush with said surface; a vehicle lift including a vertically reciprocal lift shaft extending through the bottom of the box; a pair of vertically reciprocal non-rotators coupled with the lift for preventing rotation thereof as the lift is raised and lowered; and a safety door assembly for each side of the shaft, respectively, each assembly being coupled with a respective non-rotator and movably from a retracted position within the box to an operative position substantially flush with a corresponding portion of said open top of the box in response to the upward movement of the non-rotator, each assembly including a first door panel hinged to the box at one end thereof and a second door panel shiftably coupled to the first door panel, said door panels being substantially side-by-side and coplanar with each other when the corresponding assembly is in operative position, said first door being inclined and the second door being generally horizontally disposed when the corresponding assembly is in its retracted position.
 11. In a vehicle lift assembly: a lift floor box having an open top and adapted to extend into a supporting surface with the open top substantially flush with said surface; a vehicle lift including a vertically reciprocal lift shaft extending through the bottom of the box; a pair of vertically reciprocal non-rotatorS coupled with the lift for preventing rotating thereof as the lift is raised and lowered; and a safety door assembly for each side of the shaft, respectively, each assembly being coupled with a respective non-rotator and including a pair of relatively shiftable door panels, one of the door panels being inclined and the other door panel being generally horizontally disposed when the corresponding assembly is in a retracted position, the other door panel being moveable upwardly by the corresponding non-rotator and having a lateral projection for engaging and elevating said one door panel, whereby the door panels move into respective operative positions substantially flush with a corresponding portion of the open top of the box as a function of the upward movement of the non-rotator.
 12. In a vehicle lift as set forth in claim 11, wherein said one door panel of each mechanism is hinged to said floor box near one end thereof, said one door panel having a sleeve at its innermost extremity, the other door panel having a rod pivotally mounted thereon and shiftably extending through said sleeve.
 13. A vehicle lift assembly comprising: a lift floor box having an open top; a vehicle lift having means for raising and lowering the same relative to said floor box, said lift being at least partially receivable with the floor box when the lift is in a retracted position; a pair of safety door panels for each side of the lift respectively, one of the door panels being hingedly mounted on said box and shiftably connected to the other door panel; a non-rotator for each pair of door panels respectively, said non-rotator being secured to said lift for up and down movement therewith and having means for raising the other door from retracted position in the box to an operative position substantially flush with said open top as the non-rotator is moved upwardly by said lift, said other door having means for pivoting said one door from a retracted location to an operative location substantially flush with said open top as the other door is raised. 